Ovarian cancer, a fatal gynecological malignancy, is primarily managed through surgery and chemotherapy. However, a significant challenge arises as patients frequently experience relapse due to chemotherapy resistance. This study delves into the complex functions and underlying mechanisms of macrophages in chemotherapy resistance in ovarian cancer. The single-cell transcriptome sequencing data of ovarian cancer with or without chemotherapy were analyzed. Then, corresponding cell types were identified, and macrophages were extracted from all cells. Following the standardized single-cell analysis using the Seurat package, 15 distinct macrophage clusters were found and differentially expressed genes among them were analyzed. Moreover, their association with chemotherapy resistance was explored through cell proportions and gene expression. In the single-cell transcriptomic analysis of ovarian cancer tissues before and after chemotherapy, the cellular proportion of CXCL5 CXCL5